Three Level Modified SVPWM Inverter Fed DTC Induction Motor Drive

1 PG Scholar, Department of EEE, JNTU Anantapur, Andhra Pradesh, India 2 Assistant professor, Department of EEE, JNTU Anantapur, Andhra Pradesh, India ---------------------------------------------------------------------***--------------------------------------------------------------------Abstract In this paper, a modified space vector Pulse width modulation (MSVPWM) algorithm has been developed for 3-level inverter fed direct torque control(DTC) induction motor (IMD). MSVPWM algorithm simplifies conventional space vector pulse width modulation (CSVPWM) algorithm, whose complexity lies in sector identification and will proportionalty increase with multilevel inverter output. In the proposed algorithm sectors and subsectors are identified through shifting of the modulating wave to the first sector, there by eliminating the need of reference vector position. Switching state/sequence selection is also very criticalin dealing with SVPWM fed multilevel(MLI). This is for the reason of redundancy in switching states. In the proposed algorithm out of 27 available switching states opt switching state is selected based on sectoe and subsector number, such that voltage ripple is considerably less. Dwell time of each inverter state in a given sample is also calculated using their respective modulating waves. The validate of the proposed algorithm is tested over a three level inverter fed DTC-IMD.